Development of an enzyme-linked immunosorbent assay for octylphenol

An indirect enzyme-linked immunosorbent assay (ELISA) was developed for the quantitative analysis of octylphenol. A linear carboxylated analogue of 4-nonylphenol was synthesised and characterised as hapten. The hapten was coupled to the carrier protein to produce a specific antibody. An indirect competitive ELISA method was established based on the polyclonal antibody, which exhibited an IC50 value of 51 ng/mL for octylphenol. A monoclonal antibody was produced with an IC50 value of 76 ng/mL for octylphenol. The immunoassay used with the monoclonal antibodies was applied to analyse water samples from Tai Lake in China.